+| 2026-06-04 | `d4de48c` | Copy unchanged daily aggregates inside SQLite. | First small-delta run before this commit completed in `23.6s` with `127/127` complete, `0` degraded, `CaptureModes: unchangedDelta=120, delta=7`, and `DeltaEvents: 11`. The hash change helped processing (`9.6s -> 8.1s`; Heart Rate `5.7s -> 4.2s`), but finalization stayed high (`11.4s`, Heart Rate `4.8s`). Changed daily aggregates were copying all previous daily rows through Swift before replacing affected buckets. This commit moved unchanged daily aggregate copying to SQLite `INSERT ... SELECT`, while affected buckets remain recalculated. Follow-up report completed in `21.1s` with `127/127` complete, `0` degraded, `CaptureModes: unchangedDelta=123, delta=4`, and `DeltaEvents: 50`. `SummedFinalizeElapsed` improved `11.4s -> 9.3s` and wall clock improved `23.6s -> 21.1s`; however Heart Rate finalize was still `5.0s` with `4` events, so this helped overall finalize cost but did not remove the high-volume changed-type floor. |

+| 2026-06-04 | pending | Include build identity in diagnostic reports. | The latest diagnostic report only included `App Version: 1.0(1)` near the end and did not include a commit/build source identifier. This makes it too easy to compare reports from the wrong installed binary. Diagnostics now emit `appVersion`, `buildFingerprint`, `sourceCommit`, and `sourceDirty` in `OPERATION METADATA`. `buildFingerprint` is derived from the installed executable and should change when a different binary is installed; `sourceCommit/sourceDirty` remain available for builds that inject those Info.plist keys. Expected signal: future pasted reports have enough build identity to detect wrong-version reports immediately. |

+- Reports before `reportSchemaVersion: 3` do not identify the build beyond

+  `App Version: 1.0(1)`, which is not enough for performance attribution during

+  rapid test-install iteration. Treat older report-to-commit mapping as inferred

+  from conversation/order unless backed by an external build note. New reports

+  should include `buildFingerprint`; `sourceCommit` and `sourceDirty` may still

+  be `unknown` unless the build pipeline injects those Info.plist keys.

+   `11.4s` total finalize / `4.8s` Heart Rate finalize baseline. The first

+   follow-up improved total finalize to `9.3s`, but Heart Rate stayed around

+   `5.0s`; keep this as evidence that there is still a high-volume

+   changed-type floor.

+7. Verify the next diagnostic report contains `reportSchemaVersion: 3` and

+   `buildFingerprint`. Do not compare performance reports without a build

+   identity unless the build provenance is otherwise certain. `sourceCommit`

+   and `sourceDirty` are useful when present, but may be `unknown` for normal

+   Xcode test installs.

+8. Investigate full-profile empty anchored-query cost for zero-count types.

+9. Run a non-chain-start/full-scan benchmark after skipping unchanged `verified` events and fast-pathing already-open visibility ranges. Compare `SummedInsertElapsed`, `Heart Rate insertElapsed`, `Steps insertElapsed`, and `Walking + Running Distance insertElapsed`.

+10. Reduce any remaining per-sample SQLite writes for unchanged existing samples during non-chain-start full scans.

+11. Profile whether index maintenance dominates first-import insert cost.

+12. Consider a guarded bulk-import mode for first observations:

+13. Run a fresh first-import benchmark after the unused-index removal and compare `SummedInsertElapsed`, `Heart Rate insertElapsed`, and `Active Energy insertElapsed`.

+14. Investigate whether first-import-only deferred index creation or temporary staging tables can reduce `samples` / `sample_versions` / `sample_observation_events` write cost without weakening final archive integrity.

+15. Revisit adaptive page sizes only after SQLite write-path costs are reduced.

+16. Revisit background / scheduled collection once initial import can finish reliably and post-import UI recovery is bounded.

+        lines.append("reportSchemaVersion: 3")

+        lines.append("appVersion: \(Bundle.main.appVersion)")

+        lines.append("buildFingerprint: \(Bundle.main.buildFingerprint)")

+        lines.append("sourceCommit: \(Bundle.main.sourceCommit)")

+        lines.append("sourceDirty: \(Bundle.main.sourceDirty)")

+        lines.append("Build Fingerprint: \(Bundle.main.buildFingerprint)")

+        lines.append("Source Commit: \(Bundle.main.sourceCommit)")

+        lines.append("Source Dirty: \(Bundle.main.sourceDirty)")

+

+    var sourceCommit: String {

+        let value = infoDictionary?["HPSourceCommit"] as? String

+        return value?.isEmpty == false ? value! : "unknown"

+    }

+

+    var sourceDirty: String {

+        let value = infoDictionary?["HPSourceDirty"] as? String

+        return value?.isEmpty == false ? value! : "unknown"

+    }

+

+    var buildFingerprint: String {

+        guard let url = executableURL,

+              let values = try? url.resourceValues(forKeys: [.contentModificationDateKey, .fileSizeKey]) else {

+            return "unknown"

+        }

+        let modified = values.contentModificationDate?.timeIntervalSince1970 ?? 0

+        let size = values.fileSize ?? 0

+        return "\(appVersion)-\(Int(modified))-\(size)"

+    }